Enabling Field Robotics Research with the Otter Uncrewed Surface Vessel and ROS 2

Core Concepts

This paper presents OtterROS, an open-source ROS 2 solution for the Otter uncrewed surface vessel (USV), enabling field robotics researchers to leverage the Otter platform for their work.

Abstract

The paper starts by surveying commercially available USVs and highlighting the selection of the Otter USV by the Offroad Robotics research group. It then discusses the mechanical design, power and data interfaces, and software middleware options for USV autonomy, ultimately choosing ROS 2 as the preferred platform. The core of the paper focuses on the development of OtterROS, a ROS 2 package that enables communication between the Otter USV and ROS 2 applications. OtterROS provides a publisher-subscriber architecture to allow users to interact with the Otter's onboard computer through ROS 2 topics. The paper includes details on the available data topics, external command topics, and an example control application built on OtterROS. The paper also covers the hardware integration required to run OtterROS on the Otter USV, including the computing platform, power distribution, and supporting components. Lessons learned from extensive field testing of the Otter USV are shared, covering system performance, environmental factors, and human interaction challenges. Overall, the paper aims to lower the barrier of entry for field robotics researchers to work with uncrewed surface vessels by providing the OtterROS software solution and sharing insights from the Offroad Robotics team's experience with the Otter USV.

Stats

The Otter USV has a maximum speed of 3 m/s and a payload capacity of 30 kg. The Otter USV is rated for Sea State 2 (0.5 m wave height) conditions. The Otter USV has a runtime of up to 20 hours at 1 m/s.

Quotes

"Aquatic mobile robots have the potential to become vital tools for environmental monitoring, infrastructure assessment, emergency response, shipping and transportation." "Unfortunately, researchers with an interest in uncrewed surface vessel (USV) autonomy have been limited by the number of available platforms that are suitable for research purposes."

Key Insights Distilled From

OtterROS

by Thomas M. C.... at arxiv.org 04-09-2024

https://arxiv.org/pdf/2404.05627.pdf

Deeper Inquiries

How can the OtterROS software be extended to support additional sensors and payloads beyond the current implementation?

To extend the capabilities of the OtterROS software to support additional sensors and payloads, several steps can be taken: Integration of New Sensors: New sensors can be integrated into the OtterROS framework by developing ROS nodes that subscribe to the sensor data topics and process the information accordingly. These nodes can then publish the processed data to new ROS topics within the OtterROS ecosystem. Custom Message Types: If the new sensors require custom message types, these can be defined in the ROS package associated with the new sensors. By creating custom messages, the data from the sensors can be structured in a way that is compatible with the existing OtterROS architecture. Expansion of Communication Protocols: If the new sensors use different communication protocols, adapters or translators can be developed to ensure seamless integration with the OtterROS system. This may involve converting data formats or protocols to align with the standards used within OtterROS. Hardware Interface Development: For physical payloads that require specific hardware interfaces, such as actuators or controllers, custom hardware interfaces can be designed and integrated into the Otter's payload box. This would involve ensuring compatibility with the existing power and data distribution systems. Testing and Validation: Once the new sensors and payloads are integrated, thorough testing and validation should be conducted to ensure that the data is being transmitted accurately, processed correctly, and that the overall system performance meets the requirements of the research objectives. By following these steps, the OtterROS software framework can be extended to accommodate a wide range of sensors and payloads, enhancing the versatility and research capabilities of the Otter USV.

What are the potential limitations or drawbacks of the backseat driver interface provided by the Otter USV, and how could these be addressed in future versions or alternative USV platforms?

The backseat driver interface provided by the Otter USV, while functional, may have some limitations and drawbacks that could be addressed in future versions or alternative USV platforms: Limited Control Parameters: The backseat driver interface may offer limited control parameters for fine-tuning the behavior of the USV. Future versions could provide more granular control options to researchers, allowing for more precise navigation and operation. Lack of Real-Time Feedback: The interface may not provide real-time feedback on critical parameters such as motor RPM values or position uncertainty. Enhancements could include incorporating additional sensors or telemetry systems to provide more comprehensive feedback to operators. Communication Reliability: In cold conditions, the Otter may experience network dropouts, impacting communication with the backseat driver interface. Future versions could implement redundant communication systems or improved network protocols to ensure reliable data transmission. Integration with Autonomy Systems: The backseat driver interface may not fully support integration with advanced autonomy systems or external control algorithms. Future versions could be designed to seamlessly integrate with ROS-based autonomy frameworks, allowing for more sophisticated control strategies. User Interface Design: The user interface of the backseat driver system may lack user-friendly features or visualization tools. Improvements in the interface design could enhance the user experience and make it easier for researchers to interact with the USV. By addressing these limitations and drawbacks in future versions or alternative USV platforms, researchers can benefit from more robust and versatile control interfaces that support a wide range of research applications in aquatic robotics.

What other types of field robotics research, beyond the examples provided, could benefit from the capabilities of the Otter USV and the OtterROS software framework?

Beyond the examples provided, several other types of field robotics research could benefit from the capabilities of the Otter USV and the OtterROS software framework: Environmental Monitoring: Otter USV equipped with various sensors can be used for environmental monitoring tasks such as water quality assessment, pollution detection, and habitat mapping. The data collected by the USV can provide valuable insights into environmental changes over time. Search and Rescue Operations: The Otter USV, with its autonomous navigation capabilities, can be deployed in search and rescue operations in water bodies. The USV can cover large areas efficiently and assist in locating missing persons or objects. Marine Biology Research: Researchers studying marine ecosystems can utilize the Otter USV to collect data on marine life, underwater habitats, and biodiversity. The USV can be equipped with underwater cameras, hydrophones, and other sensors to gather valuable research data. Underwater Archaeology: The Otter USV, when integrated with underwater imaging systems and sonar, can aid in underwater archaeology expeditions. The USV can survey underwater sites, map submerged structures, and assist in archaeological research projects. Oceanographic Research: The Otter USV can support oceanographic research by collecting data on ocean currents, temperature profiles, and salinity levels. The USV's mobility and endurance make it suitable for long-duration missions in various oceanic conditions. By leveraging the capabilities of the Otter USV and the OtterROS software framework, researchers in these fields can enhance their data collection, experimentation, and exploration efforts, leading to advancements in aquatic robotics research and applications.